Cylinder 7 Pressure Too Low

Common symptoms

What you'll notice

• Perform a compression test on cylinder 7 to check for any issues with the piston rings or valves.
• Inspect the fuel injector for cylinder 7 and clean or replace it if necessary.
• Check and replace the spark plug for cylinder 7 if it is worn out or faulty.
• Examine the ignition coil for cylinder 7 and replace it if it is malfunctioning.
• If all else fails, check the engine control module (ECM) for any faults related to cylinder 7 and repair or replace it if needed.

Common causes

Most likely first

1. Faulty spark plug or ignition coil in cylinder 7
2. Fuel injector malfunction in cylinder 7
3. Low compression in cylinder 7
4. Vacuum leak in the intake manifold of cylinder 7
5. Faulty engine control module (ECM) affecting cylinder 7

How to diagnose & fix

Work through it in order

1. Engine misfires or runs rough
2. Decreased power and acceleration
3. Poor fuel efficiency
4. Rough idle or stalling
5. Increased exhaust emissions or black smoke